Cromwell



(No Model.)

I (J. 0. CASE.

METHOD OF MAKING PARTS OF HOLLOW DOOR KNOBS. No. 407,817. Patented July30, 1889.

N. PEYERS Phuwulm npmr. Wilhlnglcn, D. C.

UNITED STATES CROMW'ELL 0. CASE, OF

PATENT OFFICE.

NEWV BRITAIN, CONNECTICUT, ASSIGNOR TO P. 85 F.

CORBIN, OF SAME PLACE.

METHOD OF MAKING PARTS OF HOLLOW DOOR-KNOBS.

SPECIFICATION forming part of Letters Patent No. 407,817, dated July so,1889.

To all whom it may concern/.-

Be it known that I, CROMWELL 0. CASE, a citizen of the United States,residing at New Britain, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements in theMethod of Making Parts of Hollow Door-Knobs, of which the following is aspecification.

My invention relates to improvements in the method of making parts ofhollow doorknobs; and the objects of my improvement are economyinconstruction and general efficicncy and durability of the product.

In the accompanying drawings, Figure l is a side elevation of acast-metal knob-shank formed in accordance with my method. 2 is a sideelevation of that part of the knob shell which is to be secured to saidshank. Fig. 3 is a plan view of said shell. Fig. 4: is a plan View ofsaid shell and shank ina partially-finished condition. Fig. 5 is asectional View of the same on line x x of Fig. 4, and Fig.

6 is a side elevation in the final form.

My invention relates particularly to making the knob-shank and one partof the shell which forms the hollow knob and securing them together. Theother half of the knobshell, which is not shown, may be attached in anyordinary manner and is not peculiar to my present invention.

A designates a cast-metal knob-shank having the ordinary axial hole forthe square spindle, an outwardly-proj ecting flange 7, and a tenon 8,having side recesses 9.

B designates the half knob-shell, which is struck up of sheet metal,with a centrally-projecting hub 10, which is first formed with a solidend, in the removing of which portions of the metal are left and turnedinward to form the projections 11, (see Figs. 3 and 5,)

Fig.

Application filed May 16, 1889. Serial No. 310,966. (No model.)

for fitting into the recesses 9 of the tenon S, as shown most clearly inFig. 5.

The parts A and B being thus formed, are placed together in the manneralready indicated and the tenon S spread outwardly, as shown in Figs. iand 5, to firmly secure together the parts A and B. In thus heading orspreading out the tenon 8 it will split or divide into prongs, as shownmost clearly in Fig. 4, the splits or divisions being on a line with thecorners of the spindle-hole. The projections 11 in the recesses 9prevent the parts A and B from rotating one upon the other, while thebending over of the tenon 8 prevents the parts from being disconnected.In order to make a better finish and at the same time to still morefirmly secure the parts together, the flange 7 is forced down upon thehub 10 of the shell B and formed into the head 12. (Shown in Fig. 6.)This latter operation is best done by spinning in a lathe or in a machine specially designed for that purpose.

By my method of making the knob parts I produce a neat and substantialknob shank and shell in a simple and inexpensive manner.

. I claim as my invention That improvement in the method of making partsof knobs which consists in providing the knob shank A and shell B,having, re-

spectively, the flange 7 and hub 10, securing the parts together byspreading out or headin g the end of the knob-shank, and turning theflange 7 down upon the end of the hub 10 of the shell, substantially asdescribed, and for the purpose specified.

CROMWELL 0. CASE. Witnesses:

A. N. ABBE, CHARLES F. CoRBIN;

